


Vocabulary

by socksuckinglips



Series: Daddy's Little Boy [2]
Category: Supernatural
Genre: Anal Fingering, Bestiality, Come as Lube, Coming Untouched, Dirty Talk, Extremely Underage, Knotting, M/M, Multi, Parent/Child Incest, Rimming, Sex with Sentient Animals, Sibling Incest, Sloppy Seconds, Uncle/Nephew Incest
Language: English
Status: Completed
Published: 2014-10-10
Updated: 2014-10-10
Packaged: 2018-02-20 13:55:12
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,894
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2431280
Author URL: https://archiveofourown.org/users/socksuckinglips/pseuds/socksuckinglips
Summary: <blockquote class="userstuff">
              <p>Cas wants to use some new words while he plays with his Daddy and his Uncle Sammy</p>
            </blockquote>





	Vocabulary

**Author's Note:**

> Cas is Dean's 11 year old son. Sam is a dog shapeshifter. This is all kinds of dirty bad wrong so please proceed with caution.

“Daddy?”

 

Dean puts his paper down and looks up to see Cas standing in the living room doorway. He smiles at his son's tousled hair and flushed cheeks, marveling that Cas just gets prettier every day.

 

“What is it, Cas?” Dean pulls his reading glasses off and folds them, placing them on the side table.

 

Cas frowns, holding his hand up in front of his chest. “Daddy, something … happened.”

 

Dean rushes to Cas's side, kneeling down to look at Cas's outstretched hand.

 

“Baby, are you alright? Did you hurt yourself?” Dean fusses, going to grab Cas's hand before his son snatches it away.

 

“No, Daddy, not like that.” Cas rolls his eyes, a gesture that had become more and more popular as Cas got close to turning 12. “It's not bad, I just...” Cas bites his lip, looking up at Dean through his eyelashes.

 

“I was playing with myself and it … I think some jizz came out.”

 

Dean feels a warmth bloom in his chest, that secret desire that always consumes him when it comes to Cas. The idea of Cas shooting a tiny little baby load makes Dean's cock twitch.

 

“Really, baby?” Dean delicately takes Cas's hand, laying it in his palm. “Right here?”

 

A few paltry streaks of clear liquid cling to Cas's pale skin, shiny in the lamp light as Dean inspects them.

 

“Yeah, I think so, buddy.” Dean smiles and pulls Cas in for a hug. “That's great, Cas, you're a big boy now.”

 

“It's ok, really? I thought it wasn't supposed to happen until I was a grown-up, like you and Uncle Sammy.” Cas narrows his eyes suspiciously as Dean laughs.

 

“Well, you'll make a lot more of it when you're older, but it's totally normal.” Dean lets his hands run down the slender curve of Cas's back, cupping Cas's butt to pull him onto Dean's lap.

 

“Will I come as much as Uncle Sammy when I'm big?” Cas bats his eyelashes wraps his legs around Dean's waist, wriggling against him. Dean smiles, stroking his fingers up and down the dip of Cas's spine under his t-shirt. He loves it when Cas is like this, flirtatious and affectionate.

 

“I don't think so, buddy.” Dean pulls Cas in a little closer, letting the narrow span of his ass rest on top of Dean's quickly-swelling cock. “And Sam only comes like that when he's Uncle Sammy, anyway. I think that's a special doggie thing.”

 

Cas giggles a little, squirming more and laying his hands over Dean's chest. “I like how much Uncle Sammy comes when he's a doggy.”

 

“I know you do.” Dean arches an eyebrow and scoots Cas in a little closer, rocking his hips up so he can feel the pleasure of his cock grinding against his son's sweet, slender little body. Maybe it was growing up with a shape-shifting brother, maybe it was the more-than-brothers relationship he'd had with Sam his whole life – Dean had gotten over any guilt about his special time with Cas a long time ago, just like Sam had gotten over any qualms about fucking Cas while he was “Uncle Sammy,” Cas's affectionate nickname for Sam when he shifted into a huge dog.

 

“Is that what you were thinking about when you were playing with yourself? Uncle Sammy playing with your little boyhole, putting all that doggy come in there?”

 

Dean can see the outline of Cas's little dick starting to stand up in his briefs. Dean's fully hard under Cas's squirming form, imagining his little son bent over while Sam's huge dog cock pounded into him. They'd been doing it for two years now and it never got old, especially the sounds Cas made as he took Sammy's big knot like a pro.

 

Cas's cheeks flush red as he casts his eyes down, his lip worried between his teeth. “No, I was thinking about … other stuff.” Cas's fingers twist into the hem of his shirt. He's nervous about something.

 

“Other stuff?” Dean slows the grind of his hips and pats his hand against Cas's slim thigh. “You can tell me, buddy. Were you thinking about girls?”

 

Cas's face is a picture, screwed up like Dean must be crazy to even mention that. “Gross, no.” Cas laughs and rolls his eyes. “I was thinking about, like, saying things.”

 

“What kind of things?” Dean asks softly, reaching up to tuck a stray lock of hair behind Cas's ear.

 

“Dirty things.” Cas says it so softly Dean just barely hears it. He looks up at Dean and seems to gain some confidence at the encouraging smile Dean has on his face.

 

“The kids at school say things, I know I'm not supposed to say them, and I don't, Daddy, I don't.” Cas shakes his head fervently as Dean shushes him.

 

“Hey, hey, it's alright, buddy, I went to school, too, you know.” Dean smiles softly. “You can tell me.”

 

“I won't get in trouble?” Cas narrows his eyes and tilts his head like he's not quite sure he can trust Dean.

 

“I swear.” Dean lays his palm over his heart and smiles. “As long as it's just around me or Sam.”

 

Cas grins a little sheepishly, his tongue darting out over his lips.

 

“Like fucking.” Cas waits, his eyes wide as Dean just smirks.

 

“Fucking,” Dean says slowly, loving the way Cas's eyes widen. He'd always had strict rules about cursing, more out of fear of Cas getting into any sort of trouble than a legitimate moral objection to it. And while Dean had always liked Cas's boyish nicknames for the very adult things they did together, it had gotten harder to hold his tongue as time went on. It's another bad habit Dean will be happy to encourage.

 

“What else, baby?” Dean slides his hand up and down Cas's leg, leaning his head back against the wall.

 

“Um, and cock.” Cas blushes, licking his lips again and driving Dean that little bit crazier.

 

“Mmmm, cock,” Dean murmurs, running his hand up far enough that he can trace his thumb over the head of Cas's cock through his briefs. “Your little cock's getting hard for Daddy, isn't it?”

 

Cas nods, huffing a little as Dean brushes his thumb up and down.

 

“It would make Daddy really happy if you told him what you said, Cas.” Dean rocks his hips up, letting Cas feel the full weight of his hard dick underneath him. “See how hard it makes Daddy?”

 

Cas has always thrived at being the center of attention, and it's no different now. He puffs his chest up as Dean slides his hand beneath the elastic of his briefs, wrapping his hand around Cas's stiff little dick.

 

“I was playing with my pee-pee, my cock,” Cas corrects himself, gasping as Dean closes his fist. Cas's dick is still small enough to be completely covered by Dean's palm. “I said, oh, I said, I want Daddy to fuck me.” Cas's eyes slide closed as Dean starts to stroke him, twisting his wrist to tug on the sensitive head. “I want Daddy to fuck me and I want Uncle Sammy to fuck me, I want you to come in my asshole, I want to suck your cocks and oh, Daddy!”

 

Cas' eyes fly open, blinking rapidly as Dean pulls his hand back.

 

“That's so hot, baby.” Dean wraps his arms around Cas's waist and pulls him in, kissing him as Cas moans and squirms against him.

 

“You're so fucking perfect, Cas, such a good boy.” Cas beams at the praise and tries to get Dean to jerk him off again, grabbing Dean's hand.

 

“Uh-uh, baby, you're gonna come too soon. I want to see it.” Dean rolls his eyes as Cas pouts.

 

“How about this, we can do all the things you just said, baby, whatever you want, and you can say anything you feel like, ok?”

 

“Anything?” Cas's eyes widen again, his body going still.

 

“Yeah, we can talk dirty tonight, would you like that? Uncle Sammy will be home soon, we can surprise him.”

 

Cas grins, reaching between his spread legs to press his palm against Dean's hard cock. “You think he'd like that? I don't want him to be mad.”

 

“He won't be mad, baby, trust me.” Dean lifts Cas by the waist and moves him off his lap, groaning at the press of his jeans against his erection.

 

“You wanna get ready to take Uncle Sammy?” Dean slides to the floor and rears up on his knees, pulling his shirt over his head. He pulls Cas up into the same position and takes his shirt off as well before pushing Cas's briefs down around his knees. Cas's cock stands up stiff and proud, his skin still smooth and blemish-free.

 

“I want...” Cas trails off, casting his eyes down to the floor.

 

“You can tell me, baby, remember? Anything you want.” Dean smiles softly and chucks Cas under the chin.

 

“I want you to lick my asshole, Daddy.” Cas almost giggles after he says it, his eyes bright blue and delighted.

 

“Fuck yeah, baby boy.” Dean grins, reaching down to undo his own fly. He sighs as his dick springs free, the head peeking through the slit of his boxers. He shucks his jeans as quickly as possible and pulls Cas in closer, Cas's cock poking against his side.

 

“Want Daddy to eat your ass, Cas?” Dean trails his fingers down to the swell of Cas's ass. “Lick your tight little boyhole open so Uncle Sammy can fuck his big doggy cock into you?” Dean gently trails his finger around Cas's tiny pucker as his lips brush against Cas's ear. “Yeah, you like that, don't you, baby? Get your little asshole nice and wet for us, fill you up with all that come and suck it out of you?”

 

“Daddy,” Cas whispers, his voice half-shocked and half-reverent.

 

“That's talking dirty, baby.” Dean runs his hand over to Cas's dick, grinding the heel of it against Cas's stiff prick.

 

“I like it,” Cas says with a big nod, a grin spreading over his face. “A lot.”

 

“Good boy,” Dean murmurs, kissing him again before gently moving Cas to turn around. “Want to bend over and show Daddy your pretty little hole?”

 

This is one of Dean's favorite sights on earth. Cas gets on his hands and knees, spreading his legs wide and angling his hips up in the air. His briefs pool around his knees, the pale blue setting off the milky whiteness of his legs. His little hole winks pink and pretty at Dean. Cas is still hairless back there, smooth and sweet as he spreads himself wide for his Daddy.

 

Cas doesn't even get a chance to start talking before Dean licks into him, palming the pink cheeks of Cas's ass to spread him wider. Cas gasps as Dean's tongue breaches into him, the point spearing in just to draw back and trace over the little furls of skin around his entrance. Cas hasn't taken Sammy's knot in a while and Dean wants to make sure he's good and ready.

 

“Oh, Daddy, yes,” Cas whines, shamelessly writhing his hips back against Dean's face. “Lick my asshole, Daddy, yes, harder!”

 

Dean drags his tongue in flat swipes over the loosened muscle, savoring every clench as Cas opens for him. He slips a finger in beside his tongue and licks around his buried knuckle as Cas squirms against it.

 

“Oh, Daddy, please,” Cas moans, rutting back against Dean's face, leaning down onto his forearms and spreading his legs wider. His tight little nuts hang between his legs, bouncing each time Dean licks into him.

 

Soon Dean has three fingers disappearing into Cas's tight, pink hole. He holds his hand still and groans as Cas instinctively starts to fuck himself back onto Dean's hand.

 

“Good boy, Cas, look how bad you need it.” Dean stretches out to reach for the lube in the side table.

 

“Need it, Daddy, need your cock in me, please.” Cas throws a petulant look over his shoulder and Dean smiles.

 

“Yeah, baby, you can have it.” Dean draws his fingers out of Cas's hole, watching how it flutters at the absence. He drizzles some lube directly into Cas's gaping hole before he slicks his own cock up.

 

Dean settles on the floor with his back against the couch, spreading his legs wide. Cas scoots backwards, ready to take it from behind before Dean turns him around.

 

“Want you on my lap, baby.”

 

Cas rolls his eyes slightly, knee-walking over to Dean with his little cock waving in front of him. Dean lets him straddle his lap, kissing him before he reaches behind Cas to spread his cheeks for him.

 

“That's it, Cas, sink down on Daddy's cock like a good boy.” Dean licks his lips and nods.

 

Cas knows what to do. He reaches behind himself and grasps Dean's cock, holding it still as he lines the head up with his wet hole. He closes his eyes as the crown of Dean's dick sinks home, lowering himself slowly until he's just past it.

 

“Little asshole's so open for me, baby.” Dean bites his lip, not wanting to rush Cas but desperate to be all the way inside him. There's nothing like the tight, slick heat of his little boy around his cock.

 

“Hngh, Daddy, feels so big.” Cas's skinny little legs tremble as he slowly takes another inch, his chest rising and falling with the effort.

 

“Feel good, baby, Daddy's big cock all hard just for you?” Dean kneads his fingers into Cas's ass cheeks, pulling him wide and wishing he could see the back view.

 

“Yes, oh, Daddy, feels good in my boy-” Cas stops himself, shaking his head as he lowers himself down further. “Your cock feels so good in my asshole, Daddy.”

 

He's so proud of himself Dean can't help but lean up to kiss him. He'd make sure Cas had lots of practice talking dirty in the future.

 

“That's my boy, take it for Daddy.” Dean groans as Cas sinks to the base, so fucking tight around Dean's cock. “Take that big cock so good, Cas, that's my boy.”

 

Cas leans forward, resting his head against Dean's chest before drawing his little hips up. Dean groans as Cas starts to ride him, fucking himself in short little rolls of his hips. His little cock slaps against his belly with each thrust, and Dean closes his eyes for a moment, just savoring the feeling of Cas's body clenching tight around him.

 

When Dean opens his eyes it's even better. Sam stands in the doorway, the groceries completely forgotten in the hall as he stares at Cas fully seated on Dean's cock. He opens his mouth to announce himself but Dean shakes his head, leaning over Cas's shoulder so he won't see him hold his finger to his lips.

 

Sam grins, big and wolfish, nodding his understanding. He tugs his shirt off silently, carefully undoing his pants and leaving the whole pile on the floor.

 

Cas makes a million beautiful noises as he rides Dean's cock, sighs and moans and breathy sounds that cover the noise of Sam stepping a little closer. Sam's dick fills to hardness in a matter of seconds, urged on as he strokes his hand over it. His eyes are glued to the pink stretch of Cas's little hole around Dean's cock, and Dean pulls Cas closer to his chest to give Sam a better view.

 

“C'mon, Cas,” Dean says fondly, looking down at his boy. “You said you wanted to practice your dirty words.” He kisses Cas, rolling up to meet him as Cas bucks down against him, before looking over Cas's shoulder and winking at Sam.

 

“Say something really dirty for Daddy.”

 

Cas curves his back, driving Dean's cock in deeper as he heaves in a breath.

 

“Want you to come in my asshole, Daddy, fuck me hard and come in my asshole and fuck me, Daddy,” he spills out, his eyes squeezed shut as he quickens his pace. “Fuck me and get me all wet inside so Uncle Sammy can put his knot in me, so he can, hngh, he can fuck me too, fuck Daddy's come back inside me until I'm full of his big doggie dick and oh, Daddy, oh, oh fuck, fuck.”

 

Sam's mouth falls so far open Dean swears he'll tease him about it later, his cock leaking hard as his hand flies over it.

 

“Yeah, baby, Daddy's gonna fuck you just the way you need, that's it.” Dean strokes a hand through Cas's hair, his face flushing red as he feels himself on the brink of coming. “Get your little asshole nice and sloppy for Uncle Sammy's doggie dick, that what you want?”

 

Cas moans, his head flying back and his body seizing up. It takes Dean a second to realize that he's coming, and he looks down in disbelief as Cas shoots a little baby load of spunk onto Dean's stomach.

 

Dean trips right after him, Cas's tight little hole clenching around him like it's trying to wring Dean's come out of his teeth. He buries himself deep and closes his eyes, pulling Cas's shoulders down as Cas squirms and shudders all around him.

 

“Sam!” Cas squeals happily, and Dean blinks his eyes open to see Sam kneeling beside them.

 

“Hey, baby.” Sam gives Cas a deep kiss, running his fingers through Cas's hair and smiling down.

 

“Did you do that, Cas?” Sam looks at the small droplets on Dean's skin. “Did you shoot that big load all over your Daddy?”

 

Cas blushes and bats his eyelashes. “S'not that big.”

 

“Looks good to me.” Sam beams at him, arching an eyebrow before he leans down and swipes his tongue right through it.

 

Dean groans, tipping his head back because he's pretty sure where this is going if he knows Sam. His brother doesn't disappoint, leaning over to kiss Dean, Cas's small little load swirling between their tongues.

 

“Mmm, I'm proud of you, Cas.” Sam pulls off of Dean's mouth and switches to Cas's, kissing into Cas's swollen mouth and sighing. “See, you taste good.”

 

Cas hums and squeezes his hole, hard enough to make Dean groan.

 

“Daddy, you're getting soft,” Cas pouts, and Dean doesn't miss the teasing look Sam gives him. It's not Dean's fault he's only human.

 

“Well, it's a good thing Uncle Sammy's here, huh?”

 

Cas turns to look at Sam, his eyes shining with excitement.

 

“Your Daddy got you nice and wet for me, didn't he?” Sam strokes himself a few times, moving around until he's behind Cas and in between Dean's legs.

 

“Wanna try something different, baby, OK?” Sam reaches down, nudging his cock against Cas's hole where it's still full of Dean's cock. “Want to change after I'm inside you.”

 

Cas shivers, nodding yes as Sam kisses along his shoulder.

 

“Want to make sure we don't waste any of your Daddy's come, right?” He presses the head of his cock against Cas's hole as Dean starts to slip out. “Gotta make sure I fuck it back into you before I knot you, don't I?”

 

Cas groans, his eyes rolling back as Dean's cock pulls out and Sam's slides right in after it. Dean slides down a little so Cas can lean over him, his hands resting by Dean's waist as he rests his head on Dean's shoulder.

 

Sam's eyes narrow down to slits as he sinks into Cas, his hair falling over his eye. Cas huffs out a breath against Dean's skin, needy and a little whiny as Sam buries himself balls-deep.

 

“Feel so fucking good like this, Cas, fuck.” Sam gives him a few shallow thrusts, biting his lip. “All wet and hot on my cock, good boy.”

 

Cas tosses his head back, looking over his shoulder.

 

“Sam,” he whines, drawing Sam's name out to three syllables. “I want your knot.”

 

Sam and Dean both laugh at that, Sam shaking his head and pushing his hair back from his eyes.

 

“Bossy,” he teases, still smiling fondly as he sinks as deep as he can into Cas's hole. “Alright, baby, you ready?”

 

“Oh my God, yes!” Cas turns back to face Dean and pushes himself back against Sam's cock.

 

Dean makes sure he's ready to take Cas's weight if he falls, but when the air around Sam shimmers Cas keeps himself upright as Sam shifts into his dog form. His massive paws curls around Cas's sides, holding him in place as his hips piston forward.

 

Cas moans, his mouth in a big open smile as Sam fucks into him furiously. Dean wouldn't mind watching but he's too comfortable underneath them, and he's seen Sam's slick, fat doggie cock spearing into his boy plenty of times. Besides, Cas's face is just as good.

 

“Sammy fucking you good, Cas?” Dean brushes Cas's sweat-damp hair off his face and smiles as Cas just mumbles out a stream of gibberish.

 

“That's it, Sammy, make sure you fuck him good and deep,” Dean husks, looking into Cas's barely-focused eyes. “Fuck his Daddy's come right back inside him, right where he needs it.”

 

Sammy pants and lolls his tongue out, his hips snapping wildly. Dean can hear each wet slap of his cock into Cas's hole, and he'd know Sam's knot was rising even if Cas didn't give it away.

 

“Oh, Daddy, oh, he's, fuck, his knot, Daddy, oh,” Cas mumbles senselessly, shaking as Sammy fucks him hard. Sam gets a few erratic thrusts in before he whines, flattening his ears back and burying his knot into Cas's hole.

 

“He's knotting you good, Cas, isn't he?” Dean kisses Cas then, licking every dirty moan out of his son's mouth as Sammy fills him from the other end. Dean's already starting to get hard again just thinking about Sammy pumping a huge load into Cas's swollen, used hole.

 

“Yeah, that's my boy, take it.” Dean pets through Cas's hair, smiling at the way Cas arches into it. “He's filling you up good, huh? Get all that doggie come deep inside you, seal it up with Daddy's jizz and stuff you up good, baby?”

 

Cas leans forward, resting his head on Dean's lap and sighing.

 

“It's so good, Daddy.” His voice sounds sleepy as he turns his cheek and leans his weight on his chest, settling his hips back where Sam's sealed inside him.

 

“Mmm, I know it is, baby,” Dean murmurs, stroking through Cas's hair for a while and smiling at Sam slung across his back. “You want Uncle Sammy to change back?”

 

Sometimes Cas got too tired to wait for Sammy's dick to go down, so Sam would change back to his human shape and pull out so Cas could rest.

 

Tonight, Cas just shakes his head and arches back against Sammy's curved form.

 

“No, I want to wait. He's so warm.”

 

Dean smiles, reaching out to give Sam a fond scratch behind the ear as he settles his head on Cas's back. Dean feels warm, too, nestled under his boys as his cock starts to fatten up again.

 

“And when he's done, I want him to lick all the jizz out of my asshole while you suck my dick, Daddy.”

 

Dean laughs and leans his head back, thinking that he couldn't have raised a better boy.

 


End file.
